CHICAGO — Moments before 10 a.m., a security guard thanked the crowd for being cooperative.

When the clock struck the hour, it became clear why: The doors of the Marriott Chicago O’Hare conference center opened, and hundreds of attendees, a majority of whom were over the age of 60, bee-lined as fast as they could to the booths.

Many had studied the color-coded map ahead of time listing each booth’s location and came prepared with a shopping plan — a scene that could easily be mistaken for a Black Friday sale. Instead, it was the Chicago International Miniatures Show.

Despite the gathering touting itself as “the World’s No. 1 Dollhouse Miniatures Show,” there aren’t many actual dollhouses. Attendees instead sift through thousands of tiny objects that fill these tiny homes: miniature sponges, chocolate fondue fountains, rocking chairs, barbecue sets, Tupperware containers or fly swatters.

The Tom Bishop show, as many attendees call it, is considered by its founder, Mr. Bishop, to be the largest dollhouse miniatures event in the world. Numbers appear to support that claim. This year, over 250 vendors traveled from 21 countries and 35 states.

More than 3,000 people attended, filling three large conference rooms, with hallway spillover. The weeklong event, from April 24 to April 30, included ticketed workshops with themes like “Lobsterfest” (focused on making miniature lobster boil accouterments); trade shows; and three days of ticketed shopping for the public.

Mr. Bishop estimates he has done over 500 miniature shows around the world, though in recent years he has downsized to only Chicago, which has been a continuous stop for nearly 40 years. Even the hotel itself is personal for Mr. Bishop: It’s where he and his wife, Leni, 77, spent the first night of their honeymoon.

In 1977, the duo relocated from Chicago to Margate, Fla., where they opened their dollhouse store, Miniland, before closing it in 1984 to focus their attention on traveling conventions. Mr. Bishop, who also worked for American Airlines for 17 years, was inspired to create his own show after attending others that “weren’t run very well,” he said.

“The largest miniature dollhouse convention” may sound like a silly distinction to some, but it is no joking matter for the sellers. For many, the Tom Bishop show is where they hope to make the bulk of their annual sales.

Teri, 77, of Teri’s Mini Workshop, who declined to give her last name, said she wouldn’t have been able to showcase her miniature nacho cheese machines, plates of gefilte fish or medical supplies (about $10) had a booth not dropped out last minute. She hoped her soft power would be her low pricing, in contrast to some other tables, where pieces can go for hundreds of dollars a pop.

If a collector wants something one of a kind, it might sell out on the first day, said Becky Evert, 68, a customer who had traveled from Denver with friends for the event. “Did I come with a budget? Yes,” she said. “Did I stay to it? No.” Of her seven years in attendance, it was the largest crowd she had ever seen.

Beth Pothen, 42, who runs Mountain Creek Miniatures and is a full-time postal worker, is a second-generation miniaturist, making items like goth furniture and Christmas cookie trays (she got her start at a Girl Scouts craft fair). She drove from Spokane, Wash., for the convention and hoped to recoup the cost of travel and labor, and then some, she said. Individual tables cost $325, and some opt to have two at their booth, according to Mr. Bishop.

While there’s value in breadth like that of Ms. Pothen’s, others distinguish themselves with a more niche focus. Kristin Castenschiold, 41, of Heartfelt Canines in Green Village, N.J., made a name for herself selling miniature dogs on Etsy — “I get some of the hair from a friend who is a pet groomer,” she said — and has since expanded to all kinds of furry friends, miniature light-up aquariums and trompe l’oeil cat litter boxes.

Margie Criner, 53, of Chicago’s Itty Bitty Mini Mart, makes miniatures as part of her full-time fine art practice (she’s currently on display at the traveling show “Small is Beautiful”), but wanted a way to make her work more accessible. Her tiny items, which include translucent Jell-O and teensy records from the rock band Television, are inspired by items she had growing up.

Ms. Criner is a part of a new generation of miniature makers, following in the footsteps of artists like Laurie Simmons, bringing the genre out from the home, into the gallery — with designs more modern and cheeky than the antiquarian selections that once came to define the miniature world.

While it can be hard to stand out, everyone described the world of miniature selling and buying as quite collaborative and joyful, and there are many reasons people have become obsessive collectors and makers.

Anita Hobson, 63, a customer from Belleville, Ill., said she came to the Tom Bishop convention with her husband to find items to add to the dollhouse her mother had started before she died. She became giddy over a working clothespin sold by Maria Fowler from Toronto’s The Little Dollhouse Company.

Meanwhile, Morgan Cressey, 30, was one of the convention’s youngest adult customers in attendance. Ms. Cressey, who works as a nanny and a server, had traveled from Spokane alone that weekend to stock up for her collection, a pastime she became fascinated with through her mother’s childhood miniatures.

A sense of community is a huge draw for people. Veronica Morales of Vero’s Miniatures said that the show was her big chance to show in the United States, which has a more robust miniature market than Mexico City, where she is based. For Tom Bishop this year, Ms. Morales sold miniatures — which she makes with her whole family — of an ofrenda, an altar for deceased relatives, and piñatas, among other items.

The current state of the miniature scene is encouraging, according to Barbara Davis, 76, a retired principal who is now the director of the school for the International Guild of Miniature Artisans, where many of the convention’s makers had either taken courses or taught.

“There’s a surge of people doing such a variety of creative miniatures,” said Ms. Davis, who attributed the change to younger and more diverse makers entering the industry today. She added that I.G.M.A., in Castine, Maine, had its largest enrollment last year in the school’s more than four decades in existence last year.

Mr. Bishop said he had already signed an agreement for the next two years with the Marriott Chicago O’Hare. But it remains up in the air whether his children — Rachel, 48, and Rebecca, 51, neither of whom currently works in miniatures professionally — will want to take the reins when Mr. Bishop, 82, is no longer the showman.

In the meantime, Mr. Bishop is excited by the current state of affairs. As he prepared for this year’s convention, he recalled telling his wife that he “hardly knows all the attendees anymore. They’re all new,” he said. “It’s growing again.” One tiny item at a time.